Cooling apparatus



- M y J. H. MORROW 2,348,560

COOLING APPARATUS Original .Filed July 5, 1941 3 Sheets-Sheet 2 w .3 s EE i W M 1 m a y 3 n 3 av 4 J05PH NORROW y 9, 1944. J. H. MORROW2,348,560

COOLING APPABATUS Original Filed July 3, 1941 3 Sheets-Sheet I5 I maww42w? 7 Patented May 9, 1944 COOLING APPARATUS Joseph H. Morrow,Hokendauqua, Pa., assignor to Fuller Company, Catasauqua, Pa., acorporation of Delaware Original application July 3, 1941, Serial No.401,053. Divided and this application March 2, 1944, Serial No. 524,757

6 Claims. (Cl. 34-180) This invention relates to the treatment ofpulverulent, granulated and crushed material in order to reduce thetemperature. More particularly, the invention is concerned with a novelapparatus for extracting the heat from such materials in a manner sothat the material flows continuously between cooling surfaces in auniform stream. The new apparatus is of general utility in cooling ofmaterials of the class described, as will be readily apparent, but, forpurposes of explanation, their use in connection with the cooling offreshly ground cement clinker only will be described.-

During the finish grinding of clinker in the manufacture of cement, thetemperature of the material rises appreciably, depending upon thecharacteristics of the clinker and the fineness to which the finishedproduct is ground, or both, and depending upon the method of grinding,especially open or closed circuit. The temperature of these varioustypes of products as they are discharged from the mill rangefrom about210 degrees F. to 300 degrees F. Some recent specifications which mustbe met by the manufacturer require that the cement must be ground toamuch higher surface area, which sharply increases the temperature, thespecifications also requiring that th cement be at a temperature ofnotmore than 125 F. in some cases, andlin order to meet this requirement itis necessary that the cement be delivered to the storage silos at atemperature not greatly exceeding the specification. In one commercialinstallation, reduction of the temperature of the freshly ground cementto not over 140 degrees F. enabled the manufacturer to meet a 125 F.specification. The handling and shipment of the cement from the storagesilos to the job results in sufiicient additional cooling to meetthisrequirement. V i

In the cooling of cement and the cooling of other materials of the classdescribed, in which the manufacture thereof is usually a continuousprocess, it is essential that the cooling of the material to the desiredreduced temperature take place at the same or greater rate than it isdischarged from the apparatus immediately in advance. In the event thatthe material is stored prior to cooling, the requirement that thecooling to the desired temperature take place at least at a rate equalto the feed means is necessary for economical operation. Failure of thecooler to handle the material uniformly and at the required rate leadsto objectionable results. Thus,

in the case of cooling cement as it is discharged from the finish mills;if the flow of material from the-mill is notreducedto the desiredtemperature in passing through the cooler it must be rehandled so as topass again through the cooler, or other means must be used to furtherreduce the temperature. If the flow of material through the cooler iserratic, so as to result in failure to handle the mill discharge, suchoperation necessitates additional handling of the material and at timesmay require the stopping of the grinding mill until the materialpreviously discharged can be cooled.

The problem thus presented is the efiicient and economical removal ofheat from material of the class described in a manner to discharge thematerial at a uniform rate.

It has been the practice heretofore to reduce the temperature of thefinished cement in a number of ways such as spraying the finishedgrinding mills, by water jacketing cement transport lines, byrecirculating the cement in storage silos or by a combination of thesemethods, but such methods are inefficient, and even when used incombination, have proved to be inadequate.

Various types of coolers are available in the prior art in which thematerial is advanced between concentric Water cooled surfaces and suchapparatuses have proved to be successful when the material treated is ina liquid form or in a perfectly dry form. However, in the treatment offinely ground material, such as finished cement,

which contains a certain amount of moisture such apparatuses have provedto be unsatisfactory due to the condensation of the moisture presentwhen the temperature is lowered. The condensed moisture accumulates inthe cooler and after short period of operation the material flow be-'comes erratic, due to the formation of semiplastic or set cement masseswhich insulate the cooling surfaces so as to cause inefiicient heattransfer and eventually cause such resistance to further movement of thematerial as to completely stop operation.

One source of the moisture present in finished cement is from the gypsumwhich is ground in with the clinker for the purposes of regulating thesetting time of the cement when it is used. As previously stated, thetemperature rises appreciably during finish grinding and. especially ifthe cement is ground in open circuit, this temperature may exceed 240degrees F. The gy sum is calclned to the hemi-hydrate at about 240degrees F.,

this reaction temperature varying with the degree of purity of thegypsum rock. Under such conditions about 1 /2 mol. of water are releasedby the gypsum during the grinding process and most of this water isretained in the stream of material as it discharges from the mill.

Another source of moisture in the finished cement results from thepractice in a number of plants of spraying the hot clinker dischargefrom the kiln with water to assist in its cooling. The greater portionof the water applied to the clinker for this purpose is converted tosteam and passes away in the atmosphere, but usually 'a small percentageis retained within the clinker. In many plants, clinker is stored in theopen where further moisture is contributed by the effect of weather.

The present invention is, accordingly directed to a method of treatingpulverulent, granular and crushed material so as to extract heattherefrom and remove moisture, so that the material is cooledefliciently and discharged continuously in its reduced temperaturecondition at a uniform and uninterrupted rate, and to an apparatuswhereby the new method may be advantageously and economically performed.

In the practice of the invention a continuous stream of material to betreated is passed to an enclosed circuit in which the material iscontinuously formed at a substantially thin bed between heat extractingsurfaces, the bed being advanced and the particles thereof agitated tocontact with the heat extracting surfaces, while maintaining thecomplete circuit under a uniform partial vacuum.

An apparatus in which the new method may be economically performedcomprises in general one or more cooler batteries with each coolerbattery having one or more cooler units. Each cooler unit comprises apair of headers in which two vertically spaced barrels are supportedwith one barrel directly over the other. Each barrel is provided with awater jacketed casing, and a hollow shaft, concentric with the casingand of slightly less diameter and having screw flights thereon, operatesto move the material through the casing. Water is circulatedcontinuously through the water jackets and hollow shafts to absorb theheat from the material. The upper casing at one end communicates throughthe header with a feed manifold which may be used to supply the materialto a number of adjacent units. The upper casing, at the end remote fromthe feed manifold, communicates directly through a header with the lowercasing, and material passing through the upper casing in one directionenters the lower casing and travels in the opposite direction. Thematerial discharges from the lower casing directly below the headerinlet and enters a hopper which receives the discharge of all the lowercasings in the battery, when more than one unit is used. The materialfrom the hopper may be directed to a second battery of coolers or tostorage or the like.

The hollow shafts are provided with trunnions at each end which arejournalled in the headers and at one end extend through the headers forconnection to individual motors, the lower shaft of each unit preferablybeing driven at a higher rate of speed than the upper to preventclogging in the header.

The casings are maintained under a partial vacuum and in order that thepressure conditions Will not develop to interfere with the uniform flowof material a duct communicating with the vacuum source is connectedadjacent the ends of each casing. In this manner, the water vaporsresulting from the reduction of temperature which usually collect at thedischarge end of each casing are quickly removed from the system. Thiseffectively insures against the formation of the layers of set cementwhich otherwise form on the cooling surfaces due to condensation of themoisture.

For a better understanding of the invention, reference is made tothe'accompanying drawings, illustrating apparatus suitable for thepractice of the new method. In the drawings Fig. 1 is an elevationpartly in section of the drive end portion of a complete cooler unit.

Fig. la. is a continuation of Fig. 1 showing the feed end of the unit.

Fig. 2 is a front elevation of one form of a complete cooling system.

Fig. 3 is a sectional view taken at the discharge end of one battery 'ofcooler units shown in Fig. 2.

Referring now to the drawings, the apparatus will be seen to compriseindividual cooling units H] which may be used singly or in combinationin a manner later to be described, the number of units used dependingupon the capacity and degree of cooling desired.

As each cooling unit is the same, only one will be described -and willbe seen to comprise front and rear hollow headers or housings ll, openat each end, and having vertically spaced openings in their inner sidewalls with'one opening directly above the other. A pair of parallelcasings I2 and I3 communicate with the interior of the headers throughthe spaced openings and are supported thereby.

Each casing carries an individual water jacket 14 which extendssubstantially the length of the casing exposed between the front andrear headers. The upper and lower Water jackets are connected at one endthrough a communicating passage I5-whereby cooling water supplied to thelower jacket from pipe l5 travels first through the lower jacket andthen through the upper jacket to pipe l1. With the flow of water in thedirection from the lower jacket to the upper jacket, pipe H is connectedthrough valve H! to a suitable drain I9. In the event it is desired toreverse the flow of water through the jackets, the valve to the drain -I9 is closed and water supply line 28 connected to pipe II, in whichevent, the water supply to the lower jacket is cutoff and pipe l6connected to a suitable, drain in a manner similar to that shown and'c'onnec'te'd to the upper jacket. I

Within each casing there is provided a hollow shaft 2! of slightly lessdiameter than "the-casing and mounted concentrically therewith. Hollowtrunnions 22 carried at the ends :or each of the shafts are providedwithreduced portions 23 which extend through openings in the outer sidesof the headers. The openings in the'ou'te'r sides of the headers aresubstantially larger than the greatest diameter of the sha'ftin'orderjtha't the shaft may be removed for repair or cleanling, anddetachable retaining plates 24 servefto seal these large openings. Eachplate 24 is'p!'0- vided with an'opening 25 through which the reducedportion 23 of the trunnion passes. Grease grooves 26 are provided in thesurfaces defining the openings 25 and maybe filled with grease through asuitable nipple '21 to prevent leakage ofmaterial at these points.

Adjacent to and beyond the reduced portion 23 the hollow trunnions arefurther reduced in diameter, as at '28, and bearings 29 carried by thedetachable plates 24 support the trunnions at this point. Thus it willbe seen that by this construction th bolts 30 holding the plates 25 inplace may be removed and the plates 24 and bearings 29 slipped from thetrunnions and the hollow shafts removed from the casings.

Caps 3! secured in a suitable manner to the bearing housings, at theforward end of the cooler unit, seal the hollow trunnions at this end,and water supply lines 32 connect to the interior of the shafts throughthe center of each cap.

The cooling water entering the hollow trunnions at this point flowsthrough the trunnions into the hollow shafts and thence into the hollowtrunnions at the opposite end of th unit. At a point beyond thesupporting bearings for these latter trunnions discharge openings 33 areprovided through which the cooling water flows to a discharge outlet 34.The discharge from the upper cooler flows to the discharge outlet of thelower cooler and the combined flow may be disposed of in a suitablemanner.

It has been discovered that upon rotation of the shaft in the bearings29 that a partial vacuum is developed due to the action of the grease.This creation of vacuum has no effect at the forward end of the unit,but at the rear end it has a tendency to draw water from the dischargeoutlet into the bearing. An air vent 35 provided in each rear bearingsuccessfully prevents this destructive action.

The trunnions at the rear end of the unit beyond the discharge openingsare extended in a solid form for connection to individual drive means36. In order that the material will be removed quickly as it dischargesfrom the upper screw the drive for the lower shaft is geared to rotatethis shaft at a slightly greater speed than the upper shaft.

The upper shaft is provided with screw flights 31 of uniform pitch whichextend from adjacent the outer wall of the front header to within thehollow portion of the rear header whereby material entering the frontheader is advanced along the shaft in a steady bed between the shaft andcasing and is discharged to the lower screw through the rear header. Aguard 38 attached to the outer wall of the front header and surroundingthe shaft and flights diverts the incoming material from the end of theshaft where it passes through the plate 24 and double screw flights 39on the shaft within the guard 38 further assisting in keeping thematerial from this opening. A similar guard 40 attached to the outerwall of the rear header and double flights 4| serves the same purpose atthe rear end of the upper screw.

The lower screw is constructed similar to the upper screw, the onlydifference being that this screw is turned end for end in order that theflights 42 advance the material through the low er casing in theopposite direction. Guards 43 and 44 and double flights 45 and 46 at therear and front end respectively of the lower screw serve to preventleakage at these ends.

The material to be treated is fed to the upper open end of the frontheader by a screw 41 which operates in a housing 48 to advance acontinuous supply of material. A connection 49 between the housing 48and the header directs the material to the upper screw.

As will be apparent, the front and rear headers are identical and toprevent the material entering the front header from passing directlythrough to the discharge opening 50 a closure plate is provided midwayof the header.

The interior of the entire cooling unit is maintained .under' a uniform.reduced. pressure. 'A

duct 52 enlarged at 53 connects the feed housing to a source of vacuum(not shown). A cover 54 closes the open upper end of the rear header anda duct 55 having an enlarged portion 56 also connects the interior ofthe unit at this point to the vacuum source. A. third duct 51 connectsthe discharge hopper 58 which receives the material from the outlet 50,after a complete run through both casings, to the duct 52 therebyconnecting the unit at this point to the vacuum source. It will be clearthat by connecting the unit at the entrance, at the discharge end of theupper shaft, and at the discharge end of the lower shaft with the vacuumsource that the pressure will be maintained substantially equal over theentire system, thereby precluding a flow of air in a direction oppositeto the flow of material which would substantially affect the dischargerate.

The apparatus thus far described constitutes a complete cooling unit andmay be used alone for the treatment of materials of the class described,and its operation is as follows.

The valves controlling the water flow are regulated to cause a flow ofcooling water through the water jackets I4 and hollow shafts M, and themotors 36 connected to their source of power to cause rotation of theshafts, with the lower shaft being rotated at a slightly greater'speedthan the upper shaft to insure against clogging of the material in thehollow rear header. The feed screw is then operated to deliver the hotmaterial to the upper portion of the front header and as the materialbuilds up on the division plate 5| and surrounds the shaft it isadvanced along between the upper shaft and casing in a thin circularbed.

The material as it is advanced contacts the casing and a portion of itsheat is absorbed by the cooling water in the jacket. As the outerdiameters of the screw flights are slightly less in diameter than thecasing, a film of material between the screw. and easing causes the rateof heat transfer to be less at this point as compared with the transferof heat .to the water circulating through the shaft. The material as itis advanced by the screws transfers a large proportion of its heat tothe water within the shaft, the screw acting as a cooling fin for thetransfer of heat to the water. The rapid rotation of the shaft causesthe coldest and heaviest water to contact the walls of the shaft tofurther increase the efficiency of the cooling along the exposed shaftarea between the flights.

Any water vapor present as the material is fed to the front header isremoved throughthe duct 52 and as the partially cooled materialdischarges from the upper screw through the rear header to the lowerscrew, the water vapors present at this point are removed.

. The material entering the lower casing is further cooled in the samemanner as is the upper casing and the discharge end of this shaft isalso connected to the source of vacuum in order to remove any watervapor present.

Due to the equalized reduced pressure maintained throughout the systemthe material flows freely and uniformly and is discharged to the hopper58 in a substantially dry condition.

In Figures 2 and 3 a complete cooling system is shown in which upper andlower batteries of four cooler units are used. a

In the practice of the inventionin a system of this type the hotmaterial is. advanced by screw 59- to each of the cooler units 1 iii inthe upper unit In the event that the cooling units of the upper battery.are capable of handling the entire feed, the; material, afterpassingthrough the units is discharged to the hopper 60, from which itmay be either distributed by the distributing crew 8 l to the lowerbattery of cooling units for additional cooling or maybe passed directlythrough the discharge duct 6.2. to the screw '63 which advancesitjto thehopper 64 of a Fnller-Kinyon pumpv denoted generally at 85,, which isadapted to cause the treated material to flow to the. desired storagesilo or packin'g house.

In the event that the feed rate is greater than can-be. handled by theupper battery of cooler units, the. excess material passes to thedischarge. duct 65 to be distributed by the screw 8! to the lowerbattery of cooler units.- Under such operating conditions the cooledmaterial from the discharge hopper til-maybe passed directly throughthe. discharge conduit 62 to screw 63.:and thence to. the conveyingsystem, or the valve 61 may be closed and this cooled material advancedby the screw El along with the overflow from discharge duct 68 to thelower battery of cooling units. The excess material which cannot behandled by the lower battery of cooling units is advanced to thedischarge duct 68 which directs this excess to the screw 63 whichadvances this excess and uncooled material along under the dischargeoutlets of the second battery of coolers where it is mixed with thematerial passing through these cooler units, It will thus be seen thatthe material to be treated can be doub1e-cooled by passing through thetwo batteries of cooling units in series, or the maximum quantitycapable of being handled by both batteries of cooling units may bepassed through thecooling units once and delivered to the conveyingsystem.

The entire system of both batteries of cooling units is maintained at auniform reduced pressure to cause uniform flow of the material and toremove moisture as it appears during the reduction of temperaturethroughout the system. To obtain this uniform reduced pressure, theHum-mer screen 89 through which the material passes to the feed screw 59is connected through a duct 10 to a source oi vacuum (not shown). Thisresults in a uniform reduced pressure through the screen and. feed screw59 to the front ends of each of the cooler units in the upper battery. Apair of diverging ducts H, 12 communicating with the discharge ends oftheupper screws in this upper battery, are connected to the source ofvacuum through the duct 13 which communicates with the feed screw 59.

A duct 14 connected to .the source of vacuum through the duct 10communicates with the discharge hopper 6G to place the discharge ends ofthe lower casings of the upper battery under partial vacuum. This duct14 also. places the screw 6| under partial vacuum and through this screwthe feed .ends of the upper casings of the lower battery are connectedto the source of reduced pressure. A pair of diverging ducts 15 and 16similar to those in the upper battery connect the discharge ends of theupper casings in the lower battery to the feed screw 6! through thesingle duct H.

A second duct 18 leading from the main source of vacuum connects to theby-pass l9 toplace the lower screw63'and the discharge ends. of thelower casings of the lower battery under the reduced pressure. Leakag ofai through the Fuller-Kinyonpump to the hopper 64' is immediatelyremoved through the by-pass l9 and duct 18, thereby insuringthat therate of feed in the system is not disturbed, and also that the heatcarried by this leakage is not transferred to the material.

The by-pass 19' has a valve therein for controlling the flow of materialthrough the by-pass. When all of the material is to be passed throughone or both of the cooling units the valve 80 will be closed. However,if it is desired to by-pass some or all of the material direct from theconveyor 59 to the hopper of the Fuller-Kinyon pump 65 the valve will beopened an appropriate amount.

The pipingfor the water connection to the water jackets and hollowshafts have not been shown in the system illustrated in Fig. 3, but itwill be obvious that this piping arrangement will be the same as shownin Figs. 1 and 1a.

This application is a division of my application for Cooling apparatus,Serial No. 401,053, filed July 3, 1941.

I claim:

1. An apparatus for treating pulverulent, granular and crushed materialcomprising a first series of material-treating units, means for feedingmaterialto be treated to the units of said first series, a second seriesof material-treating units, feed means for feeding material to betreated to said second series of units, a receiver for material treatedin said first series of units, a receiver for material treated in thesecond series of units, a passage connecting the material receiverforthe first series of. units with the material receiver for' the secondseries of units, a passage connecting the material receiver for thefirst series of units with the feed means for the second series ofunits, and means .for closing one of said passages to cause the materialfrom the receiver forthe first series of units to pass through the otherof said passages.

2.-An apparatus: for treating pulverulent, gran- .ularand crushedmaterial comprising .a 1ongi-, tudinally extending conveyor for materialtobe treated, a first series of material-treating units, each unit ofsaid series having a separate material inlet communicatingwith theconveyor and adapted to receive material to be treated therefrom, thematerial inlets to the material-treating units of said series being inalignment and spaced longitudinally along the conveyor so that aslongas-the amount of material fed by the conveyor is in excesspf thecapacity of the treating units of saidseries the excess of material willpass successively over the inlets to the units of the series andbeyond,- a discharge conduit from the conveyor beyond the lastinlet'to'a materialtreating unit .through which such excess ofmaterial-may be discharged from the conveyor,a second series ofmaterial-treating units, a material-feed means for the second series ofunits, said discharge conduit from the feed conveyor for the firstseries of units being connected to the material-feedmeans for the secondseries of units, a receiver for material treated in said first series ofunits,ia' receiver for material treated in said second series of unitsyapassage connecting the material receiyerforthefirst series of units withthe material; receiver; for the second series of units, a passageconnecting thetmaterial ru ceiver for the first series of units with thefeed means for the second series of units, and valve means for closingone of said passages to cause the material from the receiver for thefirst series of units to pass through the other of said passages.

3. An apparatus for treating pulverulent, granular and crushed materialcomprising a first series of material-treating units, means for feedingmaterial to be treated to the units of said first series, a secondseries of material-treating units, feed means for feeding material to betreated to said second series of units, a receiver for material treatedin said first series of units, a receiver for material treated in thesecond series of units, a passage connecting the material receiver forthe first series of units With the material receiver for the secondseries of units, a passage connecting the material receiver for thefirst series of units with the feed means for the second series ofunits, and a by-pass for material from the feed means for the firstseries of units, in advance of said first series of units, to thematerial receiver for said second series of units.

4. An apparatus for treating pulverulent, granular and crushed materialcomprising a, first series of material-treating units, means for feedingmaterial to be treated to the units of said first series, a secondseries Of material-treating units, feed means for feeding material to betreated to said second series of units, a receiver for material treatedin said first series of units, a receiver for material treated in thesecond series of units, a passage connecting the material receiver forthe first series of units with the material receiver for the secondseries of units, a passage connecting the material receiver for thefirst series of units with the feed means for the second series ofunits, a passage connecting the feed means for the first series ofunits, in advance of said first series of units, with the materialreceiver for said second series of units, and valve means forcontrolling the flow of material through said last-mentioned passage.

5. An apparatus for treating pulverulent, granular and crushed materialcomprising a first series of material-treating units, means for feedingma terial to be treated to the units of said first series, a secondseries of material-treating units, feed means for feeding material to betreated to said second series of units, a receiver for material treatedin said first series of units, a receiver for material treated in thesecond series of units, a passage connecting the material receiver forthe first series of units with the material receiver for the secondseries of units, a passage connecting the material receiver for thefirst series of units with the feed means for the second series ofunits, means for closing one of said passages to cause the material fromthe receiver for the first series of units to pass through the other ofsaid passages, a passage connecting the feed means for the first seriesof units, in advance of said first series of units, with the materialreceiver for said second series of units, and valve means forcontrolling the flow of material through said lastmentioned passage.

6. An apparatus for treating pulverulent, granular and crushed materialcomprising a longitudinally extending conveyor for material to betreated, a first series of material-treating units, each unit of saidseries having a separate material inlet communicating with the conveyorand adapted to receive material to be treated therefrom, the materialinlets to the material-treating units of said series being in alignmentand spaced longitudinally along the conveyor so that as long as theamount of material fed by the conveyor is in excess of the capacity ofthe treating units of said series the excess of material will passsuccessively over the inlets to the units of the series and beyond, adischarge conduit from the conveyor beyond the last inlet to amaterial-treating unit through which such excess of material may bedischarged from the conveyor, a second series of material-treatingunits, material-feed means for the second series of units, saiddischarge conduit from the feed conveyor for the first series of unitsbeing connected to the material-feed means for the second series ofunits, a, receiver for material treated in said first series of units, areceiver for material treated in said second series of units, a passageconnecting the material receiver for the first series of units with thematerial receiver for the second series of units, a passage connectingthe material receiver for the first series of units with the feed meansfor the second series of units, valve means for closing one of saidpassages to cause the material from the receiver for the first series ofunits to pass through the other of said passages, a passage connectingthe feed means for the first series of units, in advance of said firstseries of units, with the material receiver for said second series ofunits, and valve means for controlling the fiow of material through saidlast-mentioned passage.

JOSEPH H. MORROW.

